There seems to be a lot of argument here

Go get the module Class::Autouse and have a look at it.

It has both a working example of AUTOLOADing methods AND a reason for doing it ( in this case, saving memory by not loading classes in large class trees until a method is called on a class ).

It does a fair bit of stuff to achieve it, manually walking the ISA tree, anti-infinite loop protection code, etc.